What are the advantages and disadvantages of Circuit Breaker?

Circuit Breaker is a switch device that can close, carry and break the current under normal circuit conditions, and can close, carry and break the current under abnormal circuit conditions, such as short circuit and overload within a specified time. It is like a "safety guard" of the circuit, always monitoring the current in the circuit, and when an abnormality occurs, it will cut off the circuit in time to prevent the accident from expanding.

Ⅰ. Working principle of Circuit Breaker

Thermal tripping principle: There is a bimetallic strip inside the circuit breaker. When the circuit is overloaded, the current increases, and the bimetallic strip will bend and deform due to heat. The bimetallic strip is made of two metal strips with different thermal expansion coefficients. Under the heat generated by the current, the expansion degree is different, so it bends. When it bends to a certain extent, it will trigger the tripping mechanism, causing the circuit breaker to trip and cut off the circuit. For example, in a circuit that has been overloaded for a long time, such as a socket line connected to too many electrical appliances, the thermal tripper will play a role to prevent the line from overheating and causing a fire.
Principle of electromagnetic tripping: When a short circuit occurs in the circuit, the current will increase sharply instantly, generating a strong magnetic field. The electromagnetic tripper in the circuit breaker will sense this magnetic field, generate a sufficiently large electromagnetic attraction, and cause the tripping mechanism to operate, and the circuit breaker will trip quickly. This reaction is very fast, and it can cut off the circuit at the moment of short circuit to protect the equipment. For example, when the wire is accidentally short-circuited, the electromagnetic tripper can cut off the circuit in a very short time to prevent the electrical equipment from being damaged by the strong short-circuit current.

Ⅱ. Advantages of Circuit Breaker

Significant protection: When overload, short circuit, undervoltage and other faults occur in the circuit, resulting in excessive current, the circuit breaker can automatically cut off the circuit to prevent electrical equipment from being damaged by overcurrent, effectively avoid the occurrence of safety accidents such as fire, and protect the safety of equipment and personnel
Reusable: Unlike fuses, circuit breakers do not need to be replaced after operation. As long as they are reset after troubleshooting, they can continue to be used normally, reducing the cost of use and maintenance workload.
High reliability: After long-term development and technological improvement, the performance of circuit breakers is stable and reliable, and they can work normally in various harsh electrical environments to ensure the stable operation of the power system.
Diverse functions: In addition to the basic overload and short circuit protection functions, some circuit breakers also have a variety of additional functions such as leakage protection, undervoltage protection, overvoltage protection, etc., which can be selected and configured according to different application scenarios and needs to provide more comprehensive protection for circuits and equipment.
Easy to operate: The operation of circuit breakers is relatively simple, and it is easy to master and control whether it is manual or electric operation. At the same time, its status indication is clear, which can intuitively display the on-off status of the circuit, facilitating daily inspection and maintenance

Strong adaptability: Circuit breakers are available in a variety of types, specifications and rated current levels, which can meet the protection needs of circuits with different voltage levels, different load types and different capacities, and are widely used in residential, commercial, industrial and other fields

Ⅲ. Disadvantages of Circuit Breaker

High cost: Compared with some simple circuit protection devices, such as fuses, the manufacturing cost of circuit breakers is relatively high, and their prices are also more expensive, which increases the construction and maintenance costs of power systems to a certain extent

High installation and maintenance requirements: The installation of circuit breakers requires professional electrical knowledge and skills, and must be operated in accordance with strict installation specifications, otherwise it may affect its performance and protection effect. In addition, regular maintenance and overhaul are also essential. It is necessary to inspect and maintain the contacts, tripping mechanisms, operating mechanisms and other components of the circuit breaker to ensure its normal operation, which requires a high level of technical skills of the maintenance personnel.
Relatively slow reaction speed: Although the circuit breaker can cut off the circuit in time when a fault occurs, compared with fast-acting protection devices such as fuses, its reaction speed is still relatively slow, especially when the short-circuit current is very large, which may cause the fault current to cause a certain degree of damage to the equipment. However, with the development of technology, the reaction speed of some new circuit breakers has been greatly improved.

Ⅳ. Summary

In summary, Circuit Breaker has obvious advantages in improving system stability and resource protection, but at the same time, it also has certain disadvantages and limitations in terms of cost and installation and maintenance. In practical applications, it is necessary to reasonably configure and manage Circuit Breaker according to the specific needs and scenarios of the system to give full play to its advantages and reduce potential risks.